Have any of you tried this string already?

Ever since I started playing badminton four years ago, I've been using BG-65Ti but prices have increased by around 40% here (currently hovering around $7.10!). Amusedly, by clockwork, the BB-65Ti lasts me two months (I play twice daily, 1 to 1 1/2 hr. per session). I've been looking for a more durable string because of budget concerns, so the latest string I placed in my racquet is a BG-65 ($5.80).

However, I'm not happy with the performance of the string as it absolutely has very low repulsion compared to the 65Ti. Control though is superb, but I have to give all my strength just to generate the same amount of power in my smashes with the ti string.

Thus, I've been looking for a string that would give me reasonable power that is at the same time durable (sounds like an oxymoron ) and of course, relatievly cheap. I've been looking around, and have seen the BG-7 ($5.09). Its ratings (based on the Yonex chart in the package) are almost similar to the BG-65, but it's a thinner string (.69 mm vs .70mm). Am hoping the difference in thickness would help in terms of repulsion / power.

Any ideas from the forumers? Would more than appreciate it if any one of you can share your experience with this string.